Production of alkenylamines



United States Patent '0 3,110,731 PRUDUCTEDN 6F ALKENYLAM George A. Boswell, Hayward, Califi, assignor to Sheii Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Fiied Apr, 5, 1961, Ser. No. 160,788

9 Claims. (Cl. 260-583) This invention relates to a process for converting triallylic amines to diallylic amines or from diallylic amines to monoallylic amines. More particularly, it relates to an improved catalytic process for converting triallylamine to diallylarnine.

Triallylamine and diallylamine are both important chemicals of commerce, and are readily prepared by the reaction of an allyl halide, such as allyl chloride, with ammonia. When manufacturing diallylamine from allyl chloride and ammonia, however, undesirably large amounts of triallylamine are formed, and it is generally desirable to convert these to diallylamine. Various physical and chemical methods, e.g., pyrolysis, have been investigated for performing this conversion, but they are generally too expensive or too inetlicient to be of commercial interest. 7

it is an object of the present invention to provide an effective catalytic method for converting triallylic amines to diallylic amines. Another object is the provision of a catalytic process for converting diallylic amines to monoallylic amines. Another object of the invention is the provision of a relatively inexpensive method for converting triallylamine to diallylamine in high yield. Still another object is the provision of a palladium-catalyzed process for converting triallylamine to diallylamine. Provision of a new triolefinic amine is another object of the invention. Other objects will be apparent from the following detailed description of the invention.

These objects are accomplished inithe invention by the process which comprises heating an alkenyl amine having x+1 (alpha-hydro-beta,gamma-alkenyl) substituents directly connected to the nitrogen atom, x being an integer from 1 to 2, in contact with a hydrogenation catalyst, contacting the resulting product with water, and separating the alkenyl amine having x (alpha-hydro-beta-gamma-alkenyl) substituents from the water. By alphahydro-beta,gamma-alkenyl substituent is meant an alkenyl radical of the structure gamma-alkenyl)substituents on the nitrogen atom has upto 8 carbon atoms.

Typical tertiary tri(beta,gamma-alkenyl)amines useful in the process of the invention include tri(2,3-oct enyl) amine; tri(2,3 -heptenyl)amine; tri(2,3 -hexenyl)amine; tri(2,3-pentenyl)amine; and tri(2,3-butenyl)amine. Representative secondary amines are di(2,3-octenyl)amine; di(2,3-hexenyl)amine and di(2,3-butenyl)amine. Unor alkyl-substituted allylamines may also be employed. Typical of such amines are triallylamine, tri(methallyl) amine, tri(ethallyl)arnine, diallylamine, di(methallyl) amine, di(propallyl)amine, and the like. Preferred amines are, however, the unsubstituted polyallylamines, while the lower alkallylamines, particularly those wherein the alkyl substituent has from 1 to 4 carbon atoms, are also operative.

The process of the invention is equally suitable for converting triallylamines to diallylamines, and for converting diallylamines to monoallylamines. As a consequence, while the invention will be described in terms of the preferred embodiment, the preparation of diallylamine, it will be understood that it will be equally effective for the preparation of allylamine, and for the conversion of alkylated allylamines.

In the conversion of triallylamine to diallylamine, the triailylamine is heated in contact with a hydrogenation catalyst. The heating may be conducted by passing the triallylamine in the vapor hase over solid catalyst, or by heating the triallylamine in the liquid phase in intimate contact with the catalyst. The most satisfactory catalysts to use, because of the ease with which they may be separated from the reaction system, are the solid hydrogenation catalysts. Such catalysts are preferably selected from metals of groups I, II and IV through VIII of the periodic table, their alloys and derivatives such as their sulfides, oxides and chromites. Examples include silver, copper, iron, manganese, molybdenum, platinum, chromium, cobalt, rhodium, tungsten, mixtures of metals, such as copper-silver mixtures, copper-chromium mixtures, nickel-cobalt mixtures, and their derivatives such as copper oxide, copper chromite, nickel sulfide, silver sulfide, and the like. Particularly preferred catalysts are the members of the group consisting of nickel, copper, cobalt, iron, chromium, silver, palladium and platinum, and their oxides, sulfides and chromites. These catalysts may be employed in a finely divided form and dispersed in and throughout the reaction mixture, or they may be employed in a more massive state, either in essentially the pure state or supported upon or carried by an inert carrier material such as pumice, kieselguhr, diatomaceous 'earth, clay, alumina, charcoal, carbon or the like, and

the reaction mixture contacted therewith as by flowing the mixture over or through a bed 'of the catalyst or according to other methods known in they art,

The amount of the catalyst employed may vary over a considerable range depending upon the type of catalyst employed, the specific amine, the temperatures and pressures, and the like. In general, the amount of the catalyst ranges from about .1% to 35% by weight of the amine but amounts ranging from about 1% to 15% are more preferred. Depending on the several variables invoived,

it will be found that the catalyst may be recovered and reused for several batches before it becomes necessary to recharge and/or replace it.

The reaction may be conducted in any suitable apparatus of the type that is conventionally employed for hydrogenation processes. Thus, for example, the amine, catalyst and solvent, if desired, are charged to a pressureresistant vessel equipped with the .ecessary inlets and outlets, heating means, pressure gauge, thermometer, etc. After the reaction is complete, the reaction product is separated from the by-product and passed to the next step.

The reaction between the triallylamine and the catalyst is conveniently conducted at any temperature between about 50 C. and the decomposition temperature of the amine employed. The optimal temperature for the reaction will, of course, depend both on the nature of the amine and the type and the extent of surface of the catalyst. For example, when triallylamine is employed with palladium catalyst supported on carbon, best results are obtained at temperatures of about 80 C. to 200 C.; while when Raney nickel is used as the catalyst, best yields are obtained at temperatures between about 185 C. to about 250 C. Temperatures up to about 400 C. may, however, be employed.

The catalytic conversion of triallylamine may be conducted at, above or below atmospheric pressure. For example, one convenient mode of eifecting the conversion is to reflux the amine at atmospheric pressure in contact with the catalyst, the reflux temperature being about 150 C. Since somewhat better results are obtained at higher temperatures, the use of superatmospheric pressures is preferred. Thus, pressures from about 100 p.s.i.g. to about 5000 p.s.i.g. may be effectively employed, such elevated pressures being achieved by pressuring the system with an inert gas such as nitrogen, helium, argon, carbon dioxide or the like.

When brought into intimate contact with a hydrogenation catalyst under the conditions described, it has been unexpectedly found that instead of hydrogenating or cracking, the triallylamines undergo a conversion to the enamine form. Thus, triallylamine is converted to diallyl methylvinyl amine This behavior is observed for all of the triallylic amines described, the conversion taking place on only one of the three allylically-unsaturated alkenyl substituents of the amine molecule.

The resulting enamines are stable isolatable compounds and may, if desired, be separated from the reaction mixture after the catalytic step and purified in non-aqueous solvents. The enamines derived from the tertiary alpha hydro-beta,gamma-alkenyl amines will thus be di(alphahydro-beta,gamma-alkenyl)mono(gan1ma hydro alpha,

eta-alkenyl) amines.

It is convenient, however, to merely separate the catalyst and the allylamine-enamine reaction mixture and bring the latter into contact with water.

Surprisingly, it is observed that when the enamine and the Water are brought into intimate admixture, the vinyl substituent of the molecule splits oil to afford quantitative formation of diallylamine and propionaldehyde,

(CHz=CH-CH)2 the allylic double bond being unatfected by the water.

In contrast, the equilibrium of the diallylamine intermediate appears to favor the Schiifs base rather than the enamine intermediate OI-I==CHCH2 OII3CI-Iz-CH=N-CHz-CH=CH2 The intermediate then reacts with water to afford the monoallylamine and aldehyde:

N oH2=oH-cH2NH2 onnoHo CI-IZ CH-CI-Ir affording the monoallylamine in excellent yield.

The reaction between the enamine and the Water may be conducted in liquid phase at any convenient temperature. As a practical matter, the hydrolysis is best accomplished at any temperature between about 0 C. and C. and at atmosphericpressure, about 20 to about 50 C. being preferred. However, if desired, elevated temperatures, up to the decomposition temperature of the product amine, and reduced or elevated pressures, up to about 5000 p.s .i.g., may be employed. Although the hydrolysis requires at least a stoichiometric amount of water, excess of water are most convenient to employ. The recovery of product is inconvenient, however, when more than about 10 moles of water per mole of enamine are used.

The desired allylamine product is readily recovered from the reaction system by such conventional methods as steam stripping, fractional distillation, selective extraction, crystallization or any combination thereof. Since the starting polyallylamine is less soluble in Water than the product allylamine, this fact may be employed for separationof the amines from the Water phase.

The process may be conducted in a batch, semi-batch or continuous manner, with recycle of unconverted starting material if desired. It may be conducted in two steps, the first being the catalytic conversion of the polyallylamine to the intermediate followed by hydrolysis of the intermediate to the product amine. The over-all reaction may thus be written, where x+y=3,

This procedure lends itself readily to being practiced in a continuous or semi-continuous manner. In such a case, unconverted allylamine could be separated and recycled at the termination of the first step, only the enamine going on to the hydrolysis stage. For example, the catalyst may be separated from the reaction mixture by 'decanta-tion, filtration, centrifugation or the like, and the allylamine separated from the enamine by extraction, distillation, preferably at low temperature and under reduced pressure or similar methods. The enamine may thus be recovered in pure form for further handling.

Equally satisfactory is the conduct of the process of the invention by conducting both the catalytic conversion and the hydrolysis in one operation. Thus, the conversion and hydrolysis maybe conducted in one reaction system in situ, without the necessity of separating intermediates or recycling starting allylamines. In such a case the over-all reaction may be written ticed in a batchwise manner. {For example, when triallylamine is refluxed with a catalytic amount of palladium-on-carbon catalyst with water present in the reaction system, the principal products are diallylamine trol, and to maintain the catalyst in its dispersed state Solvents which may be used are preferably inert organic liquids with which the allylamine products and reactants are miscible under the conditions of the process. Typical solvents include such inert liquids as the alkanols, including methanol, ethanol, propanol, isopropanol, the buta-.

been converted to a mixture of 40% idiallylamine, and about 60% to monoallylamine.

Using the same procedure, tri(me-thallyl)amine is readily converted to di(methallyl)amine.

Example IV Anhydrous triallylamine was refluxed over 2.5% wt. of 10% palladium-on-carbon catalyst for approximately 30 minutes. At the end of that time the mixture was cooled and the catalyst filtered therefrom. The filtrate was then diluted with two volumes of water and heated to reflux. At the end of one hour, the volatile components were allowed to steam distill. The amine phase was separated from the distillate, dried over anhydrous sodium sulfate, and analyzed by gas-liquid partition nols, cyclohexanol, and the like; the ethers, including dicthyl ether, methyl ethyl ether, diisopropyl ether, dichromaiography. and nifraled .spevctmspopy' An 8 exam, tetrahydrofumn and the like; and me esters such conversion of tnallylamme to diallylamine was obtained. as ethyl acetate, amyl acetate, butyl propionate, methyl Examples 174/ formate and the like. Using the method of Example IV, the following Particularly preferred solvents are those miscible both results were obtained using the following reactants and with the allylamines and with water, since these afford conditions.

Composition of Organic Phase, percent w.

Triallyl amine, Catalyst, Pressure, Time, 7

Amount Amount Temp., C. p.s.i.g. min. Yield Triallyl Diallyl Monoal- Unknown (Wt. of amine amine lyl amine Organic Phase), g.

130 g. (0.95 mole) 2 g. Pd/O 150-160 (reflux) Atrn 15 71.8 7.9 3.9 110 157g. (1.15mole) 4g.Pd/O l Reflux Atm 30 4.9 83 8.6 3.3 125 50 g. (0.36 mole) 10 g Haney 220 200 30 42 50 8 (1 1 nick 1 Not recorded. a homogeneous reaction system, especially useful when Example VIII pracncmg themvepuon as aone'step i f th Triallylamine was heated to 150 C. in contact with The.novel i Improved features of 6 process 0 e 2 grams of 10% palladium-on-carbon catalyst for 30 mvemlon are Illustrated by the fOnOWmg exyamples it minutes. At the end of this time, the mixture was cooled Should b l however that the ekampkis and the triallylamine separated from the diallyl Z-methyl- Illa-61y luustratve and 9 be g q as l 40 vinyl amine product by careful fractional distillation. nous on appencied i Smce. the basic teachings The yield of enamine was about 85%. The product was thereof. y be varied W as W111 be understood. by characterized by its infrared spectrum and by its hydrolysis one skilled 1n the art. In the examples, the proportions to dianylamine and propionaldehyde. are expressed 1n parts by weight unless otherwise noted.

Example I Example IX A mixture containing grams of triallylamine, 1.5 172 grams of triallylamine and 35 grams of 10% grams of carbon-supported palladium catalyst palladium-on-carbon catalyst were refluxed together for palladlunflfli and 3 grams offvater was beatad to reflux 30 minutes. To the resulting mixture was added 300 lo,mlnutes- The fofmatlon of Proplonaldehyde was 0 ml. of water and the mixture was refluxed for an hour. lmmedlately detected Its odor- At the end of this time, the volatile components were At the end of that time, the mixture was cooled and allowed to Steam diStflL the catalyst h f The liquid Phase analyze? Gas-liquid chromatographic analysis of the organic y gas'hquld PaI t1t1On chromatography- The composl' phase of the distillate showed it to consist of 61 grams of 9 of h reaction mlxlure found to 80% 55 diallylamine, 3 grams of monoallylamine, 18 grams of triallylamine, 15% wt. diallylamine, 1% wt. mon0 Y alpha-methyl-beta-ethylacrolein, 31 grams of unconverted amine and the remainder a number of unidentified triallylaming, and 12 grams of unknown P I claim as my invention:

Example H 1. The process for preparing an alkenylamine selected vDiallylarnine containing 8% wt. water was allowed to from the group Consisting of a m0h0(h6ta,'gammfl-a1kestand at room temperature in admixture with 10% wt. il l and a di(beta=gamma-alkehyllamlhe {$0111 the chromium-promoted Raney nickel catalyst. Although no corresponding dialkehylamihe and tflhlkehylamlhe, h external heat was applied, the mixture became warm. SVPBChVBIY, the alkfihyl group in each Instance h i At the end of about thirty minutes, the catalyst was filtered g p t0 3 Carbon atoms, Which Comprises heating t oil. Analysis of the filtrate showed it to comprise about 65 alkfihylamihe selecfed m the group cohsishhg h 331d 80% wt. diallylamine and about 20% wt. monoallylamine. Corresponding difllKehylflmlhe and tfialkehylamlhe In tact with a solid metal hydrogenation catalyst at a tem- Example In perature between about 50 C. and about 400 C. and A mixture of 80 grams triallylamine, 50 grams isoa pressure up to 5,000 p.s.i.g. to convert one of the propanol solvent, 10 grams water and 2 grams 10% alkenyl groups in the alkenylamine to a vinyl'group, -palladium-on-carbon catalyst was heated at 85 C. for thereby producing a corresponding beta,gamma-alkenyl 60 minutes. At the end of that time, the mixture was vinyl amine, reacting the resulting product with water cooled and the catalyst filtered oil. The filtrate was and converting said alkenyl vinyl amine into the correanalyzed by gas-liquid partition chromatography and sponding beta,gamma-alkenylamine and aldehyde, and showed that about 50% wt. of the triallylamine had recovering the alkenylamine.

2. The process of claim 1 where the hydrogenation catalyst is palladium.

3. The process for preparing allylamine comprising heating diallylarnine in contact with a solid metal hydrogenation catalyst at a temperature between about 50 C. and about 400 C. and a pressure up to about 5,000 p.s.i.g., bringing the resulting product into contact with Water, and separating allylamine from the resulting mixture.

4. The process for the conversion of triallylarnine to diallylarnine comprising heating triallylarnine in contact with a solid metal hydrogenation catalyst at a temperature between about 50 C. and about 400 C. and a pressure up to about 5,000 p.s.i.g., bringing the resulting product into contact with water, and recovering the diallylamine therefrom.

5. The process of claim 4 wherein the hydrogenation catalyst is palladium.

6. The process for the conversion of triallylamine to diallylamine comprising heating triallylamine in contact with a solid metal hydrogenation catalyst at a temperature between about 100 C. and about 400 C. and a pressure from atmospheric up to 5,000 p.s.i.g. to form diallyl Z-methylvinyl amine, bringing said diallyl Z-methylvinyl amine into contact with water, and recovering diallylarnine from the resulting mixture.

7. The process of claim 6 wherein the hydrogenation catalyst is palladium.

8. The process of claim 6 wherein the hydrogenation catalyst is Raney nickel.

9. Diallyl Z-methylvinyl amine.

References Cited in the file of this patent Beilstein: Orgauische Chemie, vol. IV, page 208 (1922). 

1. THE PROCESS FOR PREPARING AN ALKYLAMINE SELECTED FROM THE GROUP CONSISTING OF A MONO(BETA,GAMMA-ALKENYL)AMINE AND A DI(BETA-GAMMA-ALKENYL)AMINE FROM THE CORRESPONDING DIALKENYLAMINE AND TRIALKENYLAMINE, RESPECTIVELY, THE ALKENYL GROUP IN EACH INSTANCE CONTAINING UP TO 8 CARBON ATOMS, WHICH COMPRISES HEATING AN ALKENYLAMINE SELECTED FROM THE GROUP CONSISTING OF SAID CORRESPONDING DIALKENYLAMINE AND TRIALKENYLAMINE IN CONTACT WITH A SOLID METAL HYDROGENATION CATALYST AT A TEMPERATURE BETWEEN ABOUT 50*C. AND ABOUT 400*C. AND A PRESSURE UP TO 5,000 P.S.I.G. TO CONVERT ONE OF THE ALKENYL GROUPS IN THE ALKENYLAMINE TO A VINYL GROUP, THEREBY PRODUCIGN A CORRESPONDING BETA-GAMMA-ALKENYL VINYL AMINE, REACTING THE RESULTING PRODUCT WITH WATER AND CONVERTING SAID ALKENYL VINYL AMINE TO THE CORRESPONDING BETA-GAMMA-ALKENYLAMINE AND ADEHYDE, AND RECOVERING THE ALKENYLAMINE. 